Many aircraft devices including brakes, steering systems and landing gear actuators, for example, have limited operation during a typical flight but have high power demands when operated. The total energy consumed by these devices during the flight is relatively low but power consumption is high.
Hydraulic systems are often used to operate such momentary-load aircraft devices. Hydraulic systems are able to distribute large amounts of power throughout the aircraft to simple devices that can easily transform hydraulic force into mechanical force. Equivalent and known electrical devices with similar power and force output are generally heavier, bulkier, and more complex and often require a gear system in order to generate the forces required.
Electrical systems could be used instead of hydraulic systems in order to operate the momentary-load aircraft devices. Electrical systems could be smaller and lighter than equivalent hydraulic systems. However, such electrical systems would have to function at relatively high voltages. This introduces other problems such as shock hazards and increased risk of arcing.
Landing gear devices including uplocks and actuators fall into the category of high power devices that are required on an intermittent basis but have low energy consumption when averaged over an aircraft flight (i.e. they are momentary-load devices). Due to safety and performance issues, landing gear must retract and extend over a short period of time.
Hydraulic accumulators have also been used on aircraft to provide emergency power, reduce peak system loads, and isolate hydraulic devices from direct interaction with other components in the system. These accumulators are placed close to the working device in order to minimize line losses, provide quick response to load demand, and reduce the probability of a line rupture between the accumulator and the device. Hydraulic accumulators have been known to be maintenance intensive, primarily due to the gas charge that is often used as the energy storage mechanism in the device.
Batteries are often used for storing energy on an aircraft. However, batteries may contain hazardous chemicals and may be disrupted by temperature changes. The weight of batteries used to store energy on an aircraft may be prohibitively heavy.
The present matter addresses at least one of the above issues.